Yarn apparatus



Nov. 2, 1943. .1. H. TRUESDAIL 2,333,273

YARN APPARATUS Filed May 2, 1942 3 Sheets-Sheet l 17bit]: .H- Huesdail INVENTOR avid I Nov. 2, 1943. H. TR S 2,333,278

YARN APPARATUS Filed May 2, 1942 3 Sheets-Sheet 2 fofinflfiaesdail INVENTOR ATTORNEY Nov. 2, 1943. J. H. TRUESDAIL. 2,333,278

YARN APPARATUS Filed May 2, 1942 3 Sheets-Sheet 3 kJo/m HZ-uesdafl Patented Nov.1943

YARN

John Howard Trueeda-ii. Richmond, Va., assignor to E. I. du Pont de Nemours a Company. Wilmington, DeL, a corporation of Delaware Application May 2, 1942, Serial No. 441,453

7 Claims. (CI. 57-90) spinning yarn in a continuous manner, the.

freshly spun yarn drawn from the spinning bath being collected on a slowly moving conveyor belt and led .under liquid treating showers and through a drying means, the final purified and dried yarn being subsequently removed from-the advancing belt and passed to a collecting device such as a rotating spool or a twisting means. where the yarn can be formed into a suitable package.

It is, of course, necessary-"in such a continuously operating process that'the speed of the take-up device be carefully correlated with that of the advancing yarn so as to prevent any possibility of the yarn 'overrlmning the belt if the take-up speed is too low, and to prevent the yarn from being removed from the belt too-soon (before drying is completed) if'the take-up speed is too high. Such a correlation of yarn spinning speed and yarn take-up speed can, to some extent, be obtained for a given yarn supported on 'and advanced by a conveyor belt by the proper combination of gears for the drivingmechanism of the take-up device crby the use of suitably driven nip rolls mounted just in front of the take-up device. Such a correlation is, however, diincult to perform since the yarn crinkles on the belt and shrinks considerably in the processing thereof. The yarn crinkle and shrinkage may vary considerably along the length thereof and thereby affect the above-said correlation of yarn M so as to correlate the speed of yarn removal with the speed at which it is collected on the belt.

It is another object of this invention to provide a means whereby the take-up speed of a belt processed yarn can be automatically and accurately correlated with the spinning speed of that yarn.

It is still another object of this invention to provide a means whereby the speed of removal of a yarn resting freely on a slowly moving conveyor belt can be controlled and, if necessary, varied so as to eifect the removal of yarn from the belt at a point spaced at a given distance from the forward end of the belt.

Other objects oi the invention will appear hereinaiter.

The present invention will be more readily understood by reference to the following detailed description when taken in connection with the accompanying drawings, wherein;

Figure 1 is a side elevational view. with parts shown in perspective of'one embodiment of the invention.- Y

- Figure 2 is a top plan view showing a portion of the apparatus shown in Figure l.

Figure 3 is a perspective view showing a modifled form of the invention.

Furthermore, when yarns from two or more spinning positions are being advanced in side- It is an object of thisinventlon to provide a processed yarn is removed from a slowly moving conveyor belt and passed to a take-up device means for controlling the speed at which a belt I The objects of this invention are accomplished. I

in general, by the use of a pair of coacting conical nip rolls adapted to be driven at a-constant speed and mounted adjacent the forward end of a slowly moving conveyor belt. The nip rolls are positioned, relative to the belt. so that yarn drawn from a point closely adjacent to the forward end of the belt will be drawn at a faster speed than yarn drawn from a point farther bac; from the end of the belt.

Referring now to Figures 1 and 2 of the drawings, reference numeral Ii designates a yarn drawn from a liquid container II. The yarn is drawn from the container by means of yarn feed wheel I! aided by displacement roller ii. The yarn is continuously forwarded, free of all tension except thatimpos'ed on the-yam by gravity, to a slowly moving conveyor belt II. The yarn accumulates on the belt in the form of small overlapp s ringlets IL.

A pair of conical nip rolls 28 and 25 are positioned adjacent the forward end'of the conveyor with the large ends of the conical rolls positioned toward the forward end of the conveyor. The nip rolls are preferably positioned slightly higher than the conveyor belt, as shown. The nip rolls 23 and 25 are mountedsubstantially above the rotating pirn 21 of a downtwister apparatus to which the yarn is passed from the nip rolls. A yarn guide 29 is positioned directly above the pirn 21. The nip rolls of the invention are thus capable of also serving as the feed rolls of the downtwister mechanism. The lower nip roll 25 may be permanently positioned in fixed bearings in the support frame 22. This roll is positively driven with a motor or other source of power (not shown) attached to the shaft thereof. For the purposes of the present invention, this lower driven roll may be driven at a constant rate of speed. Furthermore, the lower roll 25 is preferably provided with a cork surface, or other similar resilient surface. The upper roll 23 is preferably composed of a smooth metallic material provided with a wear-resistant surface such as a chromium-plated surface or the like. The upper roll may be supported in longitudinal grooves in the frame 22 so that the roll 23 rests by its own weight on roll 25." Obviously, any other manner of supporting 'the upper roll while the same rests by its own weight. or by means of additional weights, against roll 25 may be used for the purposes of the present invention. By removably resting the upper roll on to the lower roll 25, the upper roll can be lifted from the surface of the lower roll to facilitate passing the thread H between the two nip rolls. The upper roll is rotated by surface contact with the lower driven roll. Yarn guide rods 3| and 33 are provided between the rolls and the belt so as to prevent the yarn from passing from the ends of the rolls. The two nip rolls are preferably of the same size and shape and for use in forwarding textile yarns they may be about five inches long with a diameter at the smaller end of the rolls of approximately two inches. Their conicity is such that the peripheral speed of the large end of the rollers is approximately greater than that of thesmall end thereof.

In operation, the nip rolls are driven at such a rate that their peripheral velocity at the midpoint thereof is substantially equal to the'desired rate of removal of the yarn from the belt. The desired rate of removal of the yarn from the belt is substantially equal, possibly slightly slower, to the speed with which the yarn is passed on to the belt by the forwarding feed wheel i5.

With the nip rolls revolving at the desired rotational speed, the yarn being advanced by the belt is passed laterally from the belt between the stationary yarn guide means 3! and 33 and between the roll's23 and 25 in the manner indicated in the draWings the yarn passing from the belt under the lower roll then between the rolls and over the upper roll and then down to the takeup mechanism. The yarn leaving the rolls may be .wound into any desired form of package or, as illustrated, may be wound and twisted in the same operation. If the yarn is drawn from the belt at about the point A spaced from the forward thereby forward the yarn at an increased speed and thus gradually bring the point of yarn takeoil from the belt to the point A at which point it remains substantially constant during the further operation of the rolls. On the other hand, if the yarn is passed to the nip rolls from a point C on thebelt, it will be forwarded between the smaller ends of the rolls and thus at a smaller rate of speed and, therefore, the yarn will build up on the belt to substantially the point A where, again, the point of take-oi! from the belt will remain substantially constant.

' It is thus quite apparent that the apparatus of the present invention operates to control the take-oil point of the yarn from the conveyor belt by automatically changing the take-ofl speed of the yarn as it shifts from one side to the other of the given take-on? point. When, as in the case of the embodiment of the invention disclosed in Figures 1 and 2, the nip rolls constitute the feed rolls of a downtwister mechanism on whichthe yarn is collected, the change intake-off speed causes a temporary change in the amount of twist inserted in the yarn by the downtwlster mechanism. However, since the conical nip rolls of the present invention operate to automatically remove the yarn from the belt at the desired given point of yarn take-oil, any change in the' twist of the yarn is small and of short duration. The greatest change of yarn speed and twist occurs during the initial winding of each new package, since ,it is necessary at that timeto remove not only all of the advancing yarn but also that portion of the yarn that was advanced beyond the desired point of yarn take-o1! during the time required for the insertion of an empty package support on the-downtwister mechanism. Howis advanced on the slowly moving conveyor belt I! in the same manner as above described with reference to Figures 1 and 2. A pair of fixed yarn guiding .members 35 and 31 is positioned adjacent the forward end of the belt. A pair of nip rolls 23 and 25 is positioned at a slight angle to the forward end of the conveyor belt at a slight distance from he end of the conveyor belt. The apparatus operates in substantially the same way as the apparatus described'in Flgures1and2. -Theyarntakenfromthebelt at a point A from the end of the belt will pass substantially about the middle of the rolls and since the speed ofthe nip rolls is adjusted so as end of .the belt, the .nip rolls will forward the yarn from the belt at substantially the desired rate of speed and at a substantially fixedpoint spaced from the end of the belt. I If, on the other hand, the yarn-is passed to the nip rolls from-apoint B on the belt, the yarn will be passed beto maintain constant thepoint of take-off as the yarn is passed from the desired point to the middle section of the rolls, the point of yarn take-011A will remain constant. If the yarn advances on the belt to the point B, it will be removed from the belt at a faster rate of speed until the yarn backs oil on. the belt to substantially the point A. If the yarn is removed from the belt from the point C, the yarn will be removed at a slower rate of speed until it accumulates on the belt point A. a

tween the large endsof the conical rolls and 15 to Figure 4 0: the drawings, three to approximately the Y separate yarns are forwarded by the slowly 'moving conveyor belt I 9. Adjacent the desired point of take-oft of each yarn, a pair of horizontal, vertically spaced rods are mounted slightly above the row of overlapping yarn ringlets. Rods 4| and 43 are mounted above and adjacent the desired point of yarn take-off from the row 2| of overlapping yarn ringlets; Rods 45 and 41 are mounted adjacent the desired point of take-off from row 2|a of overlapping yarn ringlets, and rods 49 and are positioned adjacent the desired point of take-off from row 2|b of overlapping yam ringlets. The vertically spaced horizontal rods in each instance are spaced slightly from each other and are mounted at an angle other than 90 to the corresponding row of overlapping ringlets. A pair of conical nip rolls 23 and 25 is provided for each set of vertical spaced horizontal rods. The conical nip rolls are mounted substantially parallel to the horizontal rods and thereby function in the same manner as the nip rolls referred to in Figures 1 and 2 of the drawings above. This is clearly illustrated in Figure 4-. of the drawings. The horizontal rods in each instance function to tension the yarn sufllciently to remove the ringlets therefrom and to guide the yarn to the corresponding set of nip rolls. When the yarn is taken from the belt at a predetermined given point as in the case of removal of yarn from the row 2|a, of overlapping yarn ringlets, the nip rolls will draw the yarn across the middle portion of the rods 45 and 41 and about the middle portion of the nip rolls 23 and 25 corresponding thereto. In this in-- stance, similar to the above-described apparatus, the nip rolls are rotated at the rate of speed necessary to maintain the point of yarn take-off constant when the yarn passes over the middle portion of the rolls. If the yarn advances on the belt beyond this point as in the case of the yarn taken from row 2| of overlapping yarn ringlets, the nip rolls draw the yarn from the righthand side of the rods 4| and 43 and about the large ends of the nip rolls 23 and 25 corresponding thereto and, therefore, at a speed faster than the normal speed of yarn take-off, and thereby will bring the point of yarn take-oil back on the belt to the point where the take-off will remain constant. When the yarn is drawn from a point spaced back of the constant point of yarn take-off as in the case of the yarn removed from row 2|b of overlapping yarn ringlets, the-nip rolls 23 and' 25 corresponding to rods 49 and 5| will draw the yarn from the left-hand side of the rods and about the small end of the conical nip rolls. As a consequence, the speed of yarn take-off is slowed down to permit the row of yarn ringlets to build up on the belt to the point of constant yarn take-ofl. The apparatus shown in Figure 4 is equally applicable to the removal of yarn from a single row of yarn ringlets on a. moving conveyor belt.

Referring to Figure 5 of the drawings, a pair of yarn tensioning discs 55 and 51 are mounted to freely slide on a horizontal bar 59 The yarn discs 55 and 51 are maintained in close cooperative relationship to pinch a yarn passing therebetween by means of brackets 6| and 63 and coil springs 55 and 61. The horizontal bar 59 is positioned at an angle other than 90 to the forward end of the conveyor belt IS in the manner above described with reference to the rods of Figure 4. A pair of nip rolls 23 and 25 is positioned ubstantially parallel to the bar 59. If the yarn 1s taken from the belt at the desired point of yarn take-01f, the discs 55 and 51 will rotate about the bar 59 at substantially the middle portion thereof. If the yarn is taken from the belt at a point in the rear of said desired point of yarn take-off, the discs 55 and 51 will move to the dotted position shown in Figure 5 and thereby forward the yarn to the smaller ends of the nip rolls and at aslowerspeed to permit the build-up of the yarn on the belt to the desired point of yarn take-off. Alternatively, if the yarn is in advance of the desired point of yarn take-off on the belt, the discs, 55 and 51 will be moved in the same manner to the right- .hand side of the bar 59 and thereby forward the yarn to the large ends of the nip rolls and thereby speed up the removal of the yarn until it falls back to the desired point of yarn takeoff.

Referring to Figure 6 of the drawings, provision is made for a spring tension plate H of substam tial width adjacent the forward end of the slowly moving conveyor belt l9.

The spring plate H is positioned in converging relationship to a backing plate 13. The spring plate II and backing plate 13 exert a slight pinching tension on the yarn to remove the ringlets therefrom. The open diverging ends of the plates face the row 2| of overlapping yarn ringlets at an angle other than so as to project diagonally across the line of overlapping yarn ringlets. A pair of fixed yarn guides 15 and." are positioned adjacent the extreme edges of the plates so as to prevent the yarn from bein removed from between the plates. A pair of conical nip rolls 23 and 25 is positioned substantially parallel to the converging closed edges of the plates H and 13. When the yarn is passed from the row 2| of overlapping yarn ringlets from the desired point of yarn take-off from the belt, it will pass between the middle portion of the plates and thence to the middle portion of the nip rolls 23 and 25 which are being rotated at the speed necessary to maintain constant the point of yarn takeoil. When the yarn, on the other hand, is taken 7 from the belt at a point in advance of the desired point of yarn take-off, it will pass between the plates along the right-hand side of the plates and thence between the large ends of the nip rolls so as to increase the speed and bring the point of yarn take-off back to the desired point. On the other hand, when the yarn is taken from a point in back of the desired point of yarn takeoff it will pass between the plates at the lefthand portion thereof and thence between the smaller ends of the nip rolls and thus slow down the rate of removal of the yarn to permit the same to build up on the belt to the desired point of yarn take-off. v

It is believed clearly apparent that the conical nip rolls, in order to operate in the manner above-described, must be mounted, relative to the conveyor belt, with their longitudinal axes at any angle other than 90 to the center line of the belt. Furthermore, the large ends of the nip rolls must project in such a direction that yarn passing beyond the desired point of yarn take-off on the belt will contact the larger ends of the rolls and cause the point of yarn take-off to move back on the belt. The smaller ends of th nip rolls, on

the other hand, must project in the opposite di-' ispre ferably provided with a resilient surface, such as cork or rubber, whilethe upper nip roll is provided with a hardened metallic surface, the particular types of surfaces of' the two nip rolls have little bearing on the operativeness of the rolls.

Although the invention has particular utility in connection with a spinning process such as disclosed in British Patent. No. 379,880, wherein a freshly spun viscose rayon yarn leaving the spinning bath is deposited on a slowly advancing conveyor belt. on which the yarn is subjected to liquid purification showers and to drying, the invention is not limited. to use with such a process. The invention is applicable to any process wherein it is desired to transport a yarn or strand-like material by means of a slowly moving conveyor belt and where the yarn is to be removed from a given point of take-off on the belt.

The apparatus of this invention makes possible a completely automatic control of the point at which the yarn is removed from an advancing conveyor belt. If desired, the apparatus can, of course, be operated in a non-automatic manner by directing the yarnfrom the belt to the nip rolls by means of an eyeletguide whose position along the length of the 'nip rolls is controlled by hand in response to the point at which the yarn is at any time leaving the belt. Such a hand-operated device is, however, generally undesirable. v

Since it is obvious that manychanges and modifications can be made in the above-described details'without departing from the nature and spirit of the invention, it is to be understood that the invention is not to be limited to the details described herein except as set forth 'in the appended claims.

I claim: i

l. Yarn collecting and transferring apparatus comprising a slowly moving yarn conveyor belt, means for automatically removing the yarnfrom the belt, said means having portions of its yarn contacting surface traveling at difierent peripheral speeds so as to shift the point of yarn takeoff on the belt'to a predetermined given point spaced from the forward end of the belt.

2. Yarn collecting and transferring apparatus comprising a'slowly moving yarn conveyor belt, conical yarn forwarding nip rolls for automatically removing the yarn from the belt at such speeds as to shift the point of the yarn take-01f from the belt to a predetermined given point spaced from the'forward end of the belt.

"Although, as above described, the lower nip roll' 3. Yarn collecting and transferring apparatus comprising a slowlymoving yarn conveyor belt, means for continuously forwarding a yarn on to the rear end of said belt, conical yarn forwarding nip rolls positioned adjacent the forward end of said'belt for continuously removing the, yarn therefrom, said conical forwarding rolls positioned, relative to the belt, so that yarn drawn from a given point spaced fromthe forward end of the belt by said rolls will be drawn across the middle of saidrolls, whereas yarn drawn from a point spaced more closely'to the forward end of the belt will be drawn across the larger ends .of said rolls and yarn drawn from a point spaced farther back from the forward end of the belt will be drawn across the smaller ends of said rolls.

4. Yarn collecting and transferring apparatus comprising ,a slowly moving yarn conveyor belt, means for continuously forwarding a yarn on to the rear end of said belt, conical yarn forward.- ing nip rolls positioned adjacent the forward end of said belt for continuously removing the yarn therefrom, said conical forwarding rolls positioned, relative to the belt, so that yarn drawn from a given point spaced. from the forward end of the belt by said rolls will be drawn across the middle of said rolls, whereas yarn drawn from a point spaced more closely to the forward end of the belt will be drawn across the larger ends of said rolls and yarn drawn from a point spaced farther back from the forward end of the belt will be drawn across the smaller ends of said rolls and yarn tensioning means between said belt and said rolls. I

5. Yarn collecting and transferring apparatus as designed in claim 4 in which the yarn tension means comprises a pair of horizontal, vertically spaced rods positioned diagonally to the center line of the belt.

6. Yarn collecting and transferring apparatus as defined in claim 4 in which the yarn tension means comprises a pair of tension discs mounted to freely slide on a horizontal bar positioned diagonally to the center line of the belt.

7. Yarn collecting and transferringgpparatus as defined in claim 4 in which the yarna'tension means comprises a flexible spring plate positioned in converging changing relationship to a backing plate, the open diverging edges of said plates positioned diagonally to the center line of the belt.

JOHN H. TRUESDAIL. 

